Conformational Landscape of Supersonically Expanded 1-(Fluorophenyl)ethanols and Their Monohydrated Clusters

The effects of the presence of the ring fluorine atom on the conformational landscape of supersonically expanded isomeric 1-(fluorophenyl)ethanols and their monohydrated clusters are investigated by resonant two-photon ionization (R2PI) spectroscopy, coupled with time-of-flight (TOF) mass spectrometry. In contrast to the very simple spectrum of 1-phenylethanol, the lack of structural symmetry of the aromatic rings of isomeric 1-(fluorophenyl)ethanols generates more complicated spectra, characterized by several low-frequency progressions of bands. Their interpretation is based on the strict correspondence with theoretical predictions at the D-B3LYP/6-31G** level of theory. Monohydration of the 1-(fluorophenyl)ethanol isomers favours exclusive formation of the corresponding conformers, characterized by the O-H center dot center dot center dot O-w-H center dot center dot center dot pi, intracomplex interaction and whose excitation spectrum exhibits features attributed to the C-1-C-alpha torsion plus intermolecular water torsion.